Bear in mind that this is coming from a guy wearing a Hawaiian shirt and a kilt, so perhaps I'm not the best source for fashion advice.
As I see it, there are three priorities you should have when it comes to clothing: safety (don't go glassblowing in shorts), comfort (don't go out when it's 20 below in shorts), and utility (don't forget the importance of pockets, even in shorts). Life has shown me, however, that you should be aware that people will have expectations based on what you're wearing, and expect you to be aware of this. An illustrating example:
Several years ago, I lived in a town with an enormous number of bars (it at one point held the world record for most bars per square mile). As you might imagine, many people in such a community work late; I'd go for walks early in the morning and the streets would be deserted. One day, out for a morning stroll, I spot a guy in a Ghostbusters shirt. He's standing on the corner, apparently waiting for someone. As I approach, I see him reach into his pocket and pull out a cell phone. I think "No, it can't be; he must just be checking the time". But sure enough, he starts dialing- not just running through a contact list, actually punching in a number. Fate doesn't hand you an opportunity like this every day; so I as I walk up to him, I say "Hey! Who you gonna call?"
And he turns to me with a "what the hell do you care?" expression on his face, and replies, vaguely confused, "My friend".
